A study on multilayer formation of (Ba,Sr)TiO{sub}3 thin films on Pt electrodes by pulsed laser deposition method

摘要

As an application of high-k material, when (Ba,Sr)TiO{sub}3 (BST) films are used for high-k capacitor in DRAM, the improvement of crystallinity including a reduction of the leakage current of BST thin films is important. In this study, BST thin films are deposited divided several steps (layers) on the Pt/Ti/SiO{sub}2/Si substrate by pulsed laser deposition (PLD) method. Improvement of the crystallinity and the reduction at the leakage current were studied by making the EST film itself as a buffered layer. The sample deposited by three-steps (total thickness was 60nm) showed higher dielectric constant and lower leakage current than conventional method.